To provide a washing and drying machine and a drying machine capable of efficiently drying the laundry while suppressing a sudden rise in temperature in a sanitary space.

The washing and drying machine opens an inlet port 69a and an exhaust air duct 73 and turns on/off a heater, as needed, while a drying step is executed, so that dry air in a sanitary space is sucked into a drying air path through the inlet port 69a to be drying air. The drying air is heated by the heater in an on-state or waste heat of the heater in an off-state and then brought into contact with the laundry, to thereby improve drying efficiency of the laundry. The drying air is then discharged to the sanitary space through the exhaust air duct 73. The drying air contains less moisture content than that of drying air having being circulated in the drying air path many times, thereby preventing a sudden rise in temperature in the sanitary space.